Are recombinant gonadotrophins safer, purer and more effective than urinary gonadotrophins?

Recombinant gonadotrophins have been proposed as the gold standard for current infertility treatment. However, there is little difference between the various available urinary or recombinant gonadotrophins in terms of safety, purity or clinical efficacy. Resources committed to determining an advantage of one gonadotrophin preparation over another would be better spent on research for new treatments.